This grant describes a comprehensive program to modify and evaluate current methods to replace a diseased corneal endothelium with cultured cells. While such methods have been used successfully at keratoplasty in animals, the technique must be modified and more thoroughly evaluated before it can be used in humans. Our program will do so by studying new methods to form a new endothelial monolayer more rapidly. This time should be shortened to conform with the time restraints of surgery under general anesthesia. The monolayer must have an optimal density and evidence must be produced that the transplanted cells survive in the animal host for long periods of time. Our research program will also evaluate new applications of this technique of corneal endothelial replacement (CER). Specifically, we are interested to learn whether corneas preserved in long-term storage, which have been given a new endothelium, may be successfully used at keratoplasty. Such methods will result in better utilization of Eye Bank tissues and may resolve the shortage of such invaluable donor tissues. Finally, we will assess the antigenicity of the cultured cells since these cells may have an altered antigenicity. If this is the case, cultured cells could be used advantageously to abort graft rejection reactions.